You've disabled the generator. Now, you get to watch as the generator tears itself apart, plunging the ship into darkness. Things are going to get a lot brighter first though...

You start at the bottom of the lift. Move off straight away so that you're not crushed by falling metal, and get right to the outside of the generator area, then look back at the generator. There will be several explosions, then the generator turns into a huge ball of light and destroys itself.

When the fog clears, all that is left of the colossal generator are the bases of the ramps and a sparkling crater. Time to return to the MotherShip Core. It's dark now, so it's difficult to see, but look around for the longest cluster of hanging cables on the walls. Your exit is beneath these cables - so go across to them and go back through the door within to exit the level.